Size and performance of a semiconductor memory are an issue during manufacturing of the semiconductor memory. For example, in a read-only-memory (ROM), a contact for a ground voltage is used for a number of cells to function. However, the contact occupies layout areas. As a result, the size of the ROM increases. Moreover, the cells are connected to and share the same contact. Therefore, resistance associated with the connections between the contact and the cells increases. As a result, the performance of the semiconductor ROM is affected.